AB0438 EFFICACY OF BELIMUMAB TREATMENT FOR SYSTEMIC LUPUS ERYTHEMATOSUS AT OUR HOSPITAL
Authors: M. Mizusaki, R. Wakiya, S. Nakashima, H. Shimada, K. Sugihara, M. Kato, T. Miyagi, Y. Ushio, R. Mino, K. Chujo, T. Kameda, H. Dobashi
Journal: Annals of the Rheumatic Diseases (2022)

Background Belimumab (BEL), a monoclonal antibody against the soluble counterpart of B-cell activating factor (BAFF) has been recommended to be added in patients with SLE who do not respond adequately to standard therapy [1]. In addition to antibody production, belimumab may also affect other functions of B cells, such as antigen presentation and excretion of inflammatory cytokines. Belimumab may also have an effect on immune cells other than B cells, as they express BAFF receptors. These facts suggest that BEL administration in SLE may have an effect on various pathological conditions including cytokine production, not just antibody production. However, there are few reports on whether cytokine production is actually related to the efficacy of BEL administration in SLE. Objectives The purpose of this study was to determine the efficacy of BEL administration in patients with SLE and its effect on cytokines. Methods Patients with SLE who were started on BEL between December 2018 and December 2021 at our institution were included in this study. We retrospectively analyzed the reasons for additional BEL administration, adverse events, disease activity indicators (SLE Disease Activity Index (SLEDAI)-2K, lupus low disease activity state (LLDAS) achievement rate, anti-dsDNA antibody titer, serum complement titer, and treatment agents including glucocorticoid dose. Serum cytokine (interferon-alpha, interleukin (IL)-6, IL-10, and IL-17A) levels were measured using ELISA at the start of BEL administration, 3 months, and 6 months later. Results Five cases of SLE were included in the study. Four of the five patients were female, with a mean age of 51.4±9.6 years and a mean duration of disease of 17.4±10.0 years. The reasons for additional BEL administration were glucocorticoid reduction in five patients, refractory pericarditis in one patient, skin rash and arthritis in two patients, and immunological activity in two patients. Four of the five patients had decreased renal function below eGFR50 at the baseline. Concomitant medications at the time of BEL induction included steroids in five patients (mean prednisolone dose 12.2±12.2 mg/day), hydroxychloroquine in three patients, mycophenolate mofetil in three patients, tacrolimus in one patient, and methotrexate in one patient. The mean disease activity before the introduction of BEL was SLEDAI 4±4, and LLDAS was achieved in three patients. Twelve weeks after the start of BEL treatment, two patients had improved SLEDAI, including one patient who achieved LLDAS. Immunological activity parameters improved in one of the two patients. However, two patients flared after BEL administration and were treated with increased glucocorticoid doses. One patient with SLE on hemodialysis had thrombocytopenia, an adverse event that may have been related to belimumab treatment. Conclusion At our institution, BEL was additionally administered to SLE patients with refractory disease and was effective; with the exception of one case. Serum cytokine analysis before and after BEL treatment will be included in the discussion. References [1]Fanouriakis A, Kostopoulou M, Alunno A, et al. 2019 update of the EULAR recommendations for the management of systemic lupus erythematosus. Ann. Rheum. Dis. 2019;78:736–745. [2]Parodis I, Åkerström E, Sjöwall C, et al. Autoantibody and Cytokine Profiles during Treatment with Belimumab in Patients with Systemic Lupus Erythematosus. Int J Mol Sci. 2020;21:3463. Disclosure of Interests None declared